• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.4
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• pp.329-341
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• 2011

The object of this paper is to compare the accuracy and the characteristic of various methods of solving the geodetic inverse problem for the geodesic lines which be in the standard case and special cases(antipodal, near antipodal, equatorial, and near equatorial situation) on the WGS84 reference ellipsoid. For this, the various algorithms (classical and recent solutions) to deal with the geodetic inverse problem are examined, and are programmed in order to evaluate the calculation ability of each method for the precise geodesic determination. The main factors of geodetic inverse problem, the distance and the forward azimuths between two points on the sphere(or ellipsoid) are determined by the 18 kinds of methods for the geodetic inverse solutions. After then, the results from the 17 kinds of methods in the both standard and special cases are compared with those from the Karney method as a reference. When judging these comparison, in case of the standard geodesics whose length do not exceed 100km, all of the methods show the almost same ability to Karney method. Whereas to the geodesics is longer than 4,000km, only two methods (Vincenty and Pittman) show the similar ability to the Karney method. In the cases of special geodesics, all methods except the Modified Vincenty method was not proper to solve the geodetic inverse problem through the comparison with Karney method. Therefore, it is needed to modify and compensate the algorithm of each methods by examining the various behaviors of geodesics on the special regions.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.448-452
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• 2011

기존의 하천개수사업 치수경제성분석에서는 홍수피해경감편익 산정시 계획홍수위 이하의 홍수에 대해서 제방이 완벽히 방어한다는 가정 하에 제방으로 인한 피해경감액을 편익으로 산정하고 있다. 그러나 전통적 빈도해석 방법 및 수리수문 모형에 내재된 매개변수 불확실성으로 인하여 특정 하천구간에서 산정된 계획빈도 이하의 홍수위가 제방고에 해당하는 임계사상을 초과할 수도, 반대로 계획빈도 이상의 홍수위가 임계사상을 초과하지 않을 가능성도 있다. 이러한 불확실성은 수공구조물의 붕괴에 대한 잠재성을 가진 중요한 요인으로도 작용한다. 본 연구는 이러한 잠재적 위험도를 제방 월류위험도로 정의하고 이를 Bayesian MCMC에 의해 산정하는 방법을 제시하였다. 제시된 방법론은 4대강살리기사업 전 후에 대해 적용하였으며, 계획홍수위 저하에 따른 잠재적 홍수위험 감소 효과를 정량적으로 나타낼 수 있었다. 월류 위험도는 빈도별 홍수피해액의 피해발생 확률로서도 적용될 수 있으며, 이는 물리적 침수구역 설정의 어려움에 따른 홍수피해액 과다산정 문제 해결의 대안으로서도 의미가 있다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.5
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• pp.34-40
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• 2005

Most analyses and researches on Micro Aerial Vehicle(MAV) have focused upon propulsion, automatic control, aerodynamic configuration in low Reynolds number region, and miniaturization of telemetric parts. In the present study, a structural concept for MAV is designed by using the composite material suitable for light flight structures. In order to study the load path and stress state of the MAV, the load and structural analyses are simultaneously performed by the aeroelasticity module of MSC/NASTRAN. The stability derivatives of the MAV are obtained for three symmetric, two antisymmetric, and four unsymmetric maneuvering conditions. Although the aerodynamic theory in MSC/NASTRAN could not be proper for MAV analysis, it provides an traditional and effective tool for trim and load analyses and may be corrected with the results by more accurate theory or test. The results show that the inertial load due to payloads has a more effect on stress rather than the aerodynamic load.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.3
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• pp.124-133
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• 2011

The purpose of this study is to interpret the landscape characteristics of Changdeokgung's rear garden with the idea of Yijing(意境) the way to have a sense of an imaginative object. A term of Jing(境) in Yi-jing means a boundary of man's consciousness. On the boundary of consciousness for an imaginative object, there is a situation of man's emotion to be called Qingjing(情境) to meet an object, and beyond Qingjing, there is Yijing, a consciousness of the idea and the truth. The Structure of the Yijing is an analytical framework in this study. It is clarified that the idea of Yijing and landscape characteristics of changdeokgung's rear garden to analyze works of kings and related historical documents. In result, there were three kings named Injo, Sukjeong and Jeongjo who played big roles to develop the rear garden. First, Injo had built physical structure of the rear garden, the second Sukjong enjoyed Qingjing with composing the poems of Sangrimshipkyoung(上林十景), Jeongjo clearly had made a boundary of idea of Yijing broaden. It is an effective way to interpret imaginative characteristics of our traditional landscape through the concept of Yijing the useful way to understand and systemize a subject of idealistic consciousness.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.12
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• pp.897-903
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• 2019

This paper represents an simplified design method of hybrid composites. The proposed method is very simple compared to conventional design approaches and easy to apply to practical design problems. The method is based on not complex optimization approaches but conventional theories. The equivalent dielectric properties concept and multi-layered dielectric slab theory are an important theoretical background of the proposed method. This approach divide the design domain into several domain which have theoretically different electro- agnetic functionality. Then, the domains are expressed by equivalent dielectric properties. Numerical analysis are performed several types of design candidates. S-parameter test for final design was conducted for validate the proposed approach indirectly.

• Journal of the Daesoon Academy of Sciences
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• v.30
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• pp.201-234
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• 2018

'Woori Philosophy' is the modern philosophy of Korea. The purpose of this study is to make a hypothetical model of the methodologies used in Woori Philosophy, to analyze and classify this system of thought as it appears in the Jeon-gyeong (『典經』), to confirm the effectiveness of the model's application, and to present the model's methodological best practices. In this paper, I have made a standard for Woori Philosophy by combining existing studies. Thereby, although it is preliminary, I have presented the model as a way of achieving Woori philosophy by analysis and division of this thought in the Jeon-gyeong. As a result, the Jeongyeong's content is organized into an order in frequency which emerges as Model②, Model①, Essential Model, Model④, and Model③. These models can be evaluated to show that the Jeon-gyeong progressively inherited different schools of traditional Korean thought, while simultaneously characterizing them as Korean in many areas, never ignored the problems of the times or an awareness of the world, and furthermore, did not senselessly or blindly accept foreign objects spread into Korea from 1880~1890. Therefore, the Jeon-gyeong shows a comprehensive methodology for the implementation of Woori philosophy based on its own historical setting. It can be evaluated as the best practices which took many ideas and made those ideas its own. Through this, I was able to confirm its effectiveness as a methodology of Woori Philosophy and was able to extract its best practices. However, the ideas in the Jeon-gyeong did not directly become Woori Philosophy. To solve our problems in the 21st century, there is still an assignment to interpret these ideas through the application of this model. If the existing research on Daesoon Thought (大巡思想) is to become Woori Philosophy, then it should do so through the application of this model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4381-4387
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• 2015

Ship hull is a compound curved shape and most of shipyards have been using gas heating method for the surface forming of steel plate. This traditional forming process have problems such as difficulties in heat input control and poor working conditions due to loud noise and air contamination. Recently, researches on automatic hull forming system have been conducted using high frequency induction heating method which have good control ability and favorable working environment. In this study, the induction heating simulation system for curved surface forming of steel plate was developed and induction heating experiments were performed. Based on the results of this study, efficient induction heating coil design and optimal heating conditions for the automatic hull forming system can be obtained.

• Geophysics and Geophysical Exploration
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• v.25 no.1
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• pp.26-37
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• 2022

Recently, multiple methods using small aircraft for geophysical exploration have been suggested as a result of the development of information and communication technology. In this study, we introduce the hybrid unmanned aircraft electromagnetic system of the Korea Institute of Geosciences and Mineral resources, which is under development. Additionally, data processing and interpretation methods are suggested via the analysis of datasets obtained using the system under development to verify the system. Because the system uses a three-component receiver hanging from a drone, the effects of rotation on the obtained data are significant and were therefore corrected using a rotation matrix. During the survey, the heights of the source and the receiver and their offsets vary in real time and the measured data are contaminated with noise. The noise makes it difficult to interpret the data using the conventional method. Therefore, we developed a recurrent neural network (RNN) model to enable rapid predictions of the apparent resistivity using magnetic field data. Field data noise is included in the training datasets of the RNN model to improve its performance on noise-contaminated field data. Compared with the results of the electrical resistivity survey, the trained RNN model predicted similar apparent resistivities for the test field dataset.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.6
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• pp.409-415
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• 2021

Medical waste management is becoming increasingly important, specifically in light of the current COVID-19 pandemic, as hospitals, clinics, quarantine centers, and medical research institutes are generating tons of medical waste every day. Previously, a traditional incineration process was utilized for managing medical waste, but the lack of landfill sites, and accompanying environmental concerns endanger public health. Consequently, an innovative sterilization shredding system was developed to resolve this problem. In this research, we focused on the design and numerical analysis of a shredding system for hazardous and infectious medical waste, to establish its operational performance. The shredding machine's components were modeled in a CAD application, and finite element analysis (FEA) was conducted using ABAQUS software. Static, fatigue, and dynamic loading conditions were used to analyze the structural stability of the cutting blade. The blade geometry proved to be effective based on the cutting force applied to shred medical waste. The dynamic stability of the structure was verified using modal analysis. Furthermore, an S-N curve was generated using a high cycle fatigue study, to predict the expected life of the cutting blade. Resultantly, an appropriate shredder system was devised to link with a sterilization unit, which could be beneficial in reducing the volume of medical waste and disposal time, thereof, thus eliminating environmental issues, and potential health hazards.

• Journal of KIISE:Software and Applications
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• v.33 no.3
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• pp.344-355
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• 2006

In daily activities, the interaction between humans and robots is very important for supporting the user's task effectively. Dialogue may be useful to increase the flexibility and facility of interaction between them. Traditional studies of robots have only dealt with simple queries like commands for interaction, but in real conversation it is more complex and various for using many ways of expression, so people can often omit some words relying on the background knowledge or the context of the discourse. Since the same queries can have various meaning by this reason, it is needed to manage this situation. In this paper we propose a method that uses hierarchical bayesian networks to implement mixed-initiative interaction for managing vagueness of conversation in the service robot. We have verified the usefulness of the proposed method through the simulation of the service robot and usability test.